摘要：SummaryAcoustic micro-beams produced by highly focused ultrasound transducer have been investigated for micro-particle and cell manipulation. Here we report the selective trapping of microspheres via the acoustic force using the single acoustical beam. The forbidden band theory of acoustic radiation force trapping is proposed, which indicates that the trapping of particles via the acoustic beam is directly related to the particle diameter-to-beam wavelength ratio as well as excitation frequency of the ultrasonic acoustic tweezers. Three tightly focused LiNbO3transducers with different center frequencies were fabricated for use as selective single beam acoustic tweezers (SBATs). These SBATs were capable of selectively manipulating microspheres of sizes 5–45 μm by adjusting the wavelength of acoustic beam. Our observations could introduce new avenues for research in biology and biophysics by promoting the development of a tool for selectively manipulating microspheres or cells of certain selected sizes, by carefully setting the acoustic beam shape and wavelength.Graphical abstractDisplay OmittedHighlights•Ultrahigh-frequency (≥100 MHz) ultrasonic transducer to manipulate microspheres•The broad bandwidth and highly focused transducer differentiate microparticles•FEA modeling and calculation indicate the force for selectively trapping•The forbidden band theory of acoustic radiation force is proposed for trappingUltrasound Technology; Biochemistry Methods; Biophysics
